<!DOCTYPE html>
<html>
<head>
    <title>Bootstrap</title>
</head>
<body>
<h1>Hello, world!</h1>
<h2>Hello, world!</h2>
<h3>Hello, world!</h3>
<h4>Hello, world!</h4>
<h5>Hello, world!</h5>
<h6>Hello, world!</h6>
<a href="http://www.gench.edu.cn">上海建桥学院</a>
<hr />
<input type="text" />
<input type="button" value="点我"/>

1<input type="radio" name="aaaaaa" />
2<input type="radio" name="aaaaaa"/>
<input type="radio" name="bbb"/>

<input type="checkbox" name="cccc" />
<input type="checkbox"name="cccc" />
<input type="checkbox" name="cccc"/>

<span>描述</span>
<label>文本</label>
<button>点我2</button>
<textarea>
1111111111111
    222222222222
    33333333333

</textarea>
<div>
    1111111
    222222222

</div>

<select>
    <optgroup label="asia">
        <option>china</option>
        <option>japan</option>
        <option>korea</option>
    </optgroup>
    <option>usa</option>
</select>

</body>
</html>